Kant explicitly answers the question to ‘What is a book?’ in “Metaphysics of Morals(Die Metaphysik der Sitten)”, the first part of Metaphysical Elements of Justice(Metaphysischen Anfangsgrunde der Rechtslehre). A book is a physical product that is made to follow a production procedure, of which book owners are a part. A book is simultaneously a work of art and a discourse. The discourse is still owned by the author, even if it is duplicated in the book. Without the author’s consent, therefore, a book ought not to be transmitted or lent. The issue regarding the ownership on the discussion defining what a book is results from the complicated status of the book both as a physical product and as an aesthetic work. Even today, this issue of the identity of the book continues. In other words, a book is on one hand a work that reflects the author’s identity and consistency, while on the other it is a product that takes a form through inscription mediums. From the ancient times to the first century, their form was limited to scrolls, and the works later spread into different objects. In this process, the invention of the codex made it possible to gather the many works of one author in one binding. Today, the subject-matter of the book as an object and the book as a discourse – the relationship among objects, genres, and functions of written culture of the past – is to be reformulated. Readers who sit in front of computer screens take in selected broken fragments rather than understanding the text as a whole, and no longer differentiate genres. Digital mediums do not correspond to any clear material objects, such as the scrolls of ancient times, manuscript codex copies, or printed copies after Gutenberg. In the age of the codex whose difference was that it was immediately distinguishable among such various products of written culture as books, magazines, and newspapers, the hierarchy of objects showed the order of discourse, i. e., the hierarchy of validity in the discourse. However, now in the world of digital text, the restrictions that were coerced by the codex’s morphology and copyright legislational systems are lifted. Since the 18th century, the sort of creative writing that has overturned the criteria based on copyright and ownership has been developed. From here, there are two possibilities expected in the future. One is the possibility of the regulation and recognition of works, along with the applying devices on digital texts that follow the criteria of copyright, and the other is that readers abandon these criteria and regard the texts however they may wish and as a continuing discourse. However, the events that the history of written culture encountered, such as the advent of the codex and printing, made it possible for outcomes of the past and new technology to coexist in novel manners. The present day digital revolution also brings a reorganization of written culture. Therefore, as in the past, writings can be expected to be redistributed in forms both of the old and the new. Even so, categories formed based on the order of discourse originating from the name of the author, the identity of the work, and intellectual ownership, along with the fundamental issues raised regarding the fact that they are all linked in the digital world, still exist along with the division between the two, and even with the unprecedented phenomenon in which they are in opposition to each other.